Chuck and ratchet mechanism



14, 1956 M. s. DUNKELBERGER 2,734,413

CHUCK AND RATCHET MECHANISM Filed April 18, 1950 R m m N EE vn w JIEA Unted. States, aw

. This invention relates to a tool for operating various types ofdevices such as screw drivers, drills, socket wrenches, and the like.

A large number of ratchet mechanisms have been de vised from time totime for use in operating screw drivers and the like, but these haveeither involved a large number of delicate parts or have otherwise beenunsatisfactory The problems of providing a satisfactory ratchet type ofoperator for a screw driver is very ditficult because of the tendency ofthe ordinary screw driver to slip out of the slot in the screw andbecause of the need for applying a strong downward pressure whilerotating the screw driver. It is an object of this invention to providean improved combination screw driver and screw driver holder or operatorwhich makes it easy to hold the screw driver in place in the eye of thescrew during the screw driving operation.

It is another object of this invention to provide an inexpensive, yetdurable, tool which may be used for a large number of different uses andwhich operates in an improved manner. More particularly, it is an objectof this invention to provide an improved type of ratchet drive whichincludes a simplified means for selectively adjusting the ratchet forrotating a tool in either direction of rotation or for rotating the toolin both di rections.

Another object of this invention is to provide an improved pawl and pawlmounting arrangement.

Another object of this invention is to provide an improved relationshipbetween a ratchet type of crank and thetool to be operated thereby;

"Still another object of this invention is to provide an improved formof chuck for use in supporting the tools. I

I Other objects and advantages reside in the construction of parts, thecombination thereof and the mode of operation, as will become moreapparent from the following description.

I In the drawings:

.Figure 1 is a side elevational view; I

.Figure, 2 is an exploded perspective view showing the construction andarrangement of the ratchet mechanism;

Figure 3 is a plan view of the ratchet mechanism with the'cover removed;

'Figure 4'is a plan view with parts broken away to show the ratchet inits neutral position;

' Figure 5 is a fragmentary sectional view showing the chuck and itsrelationship to a tool mounted in the chuck;

Figure 6 is aside elevational view, with parts broken away, showing adrill unit mounted in the chuck;

.Figure. 7 is a perspective view of an adapter for use mounting a socketwrench in the chuck shown in Figure 5 and 6.

Figure 8 is a perspective view of the lower end-piec of the screwdriver; and

Figure 9 is a fragmentary elevational view showing the pawl supportingmeans.

" Referring now to. the drawings wherein I have shown a prferred'embodiment of my invention, reference numeral 10 generally designatesaratchet lever having a handle 12 rotatably mounted adjacent the one endthereof for use in imparting rotation to the main shank 14 through aratchet drive in a manner to be explained more fully hereinafter. Achuck or socket 16 is secured to the lower end of the shank 14 and isadapted to interchangeablyreceive a variety of types and sizes of toolmembers, such as screw drivers, drills, socket wrenches, Allan wrenches,and the like. i

A specially designed pressure handle 20 is rotatably' the work. Thelower portion of the pressure handle is" provided with a relatively wideflange 22 which makes it possible to exert a downward pressure withoutdanger of one's hand slipping. The upper end of the handle does not havesuch a flange and is purposely so designed that irrespective of howlarge ones hand is, one can get a firm grip-onthe pressure handle. Asleeve 23, which is disposed between the handle 20 and the ratchetlever' 10, holds the pressure handle against the upper end ofthe chuckas shown. It should be noted that the handle 20 is placed next to thechuck, whereby it is possible to accurately'guidethe tool held by thechuck.

Generally speaking, no amount of downward pressure will keep a poorlydesigned screw driver from slipping out of place. The most common formsof screw drivers have a straight shank with a fixed handle arrangeddirectly in alignment with the shank, so as to enable the user to alignthe screw engaging portion with the eye of the screw. Even with theseconventional screw driver's,

it is ditficult to keep the axis of the screw driver properly lined upwith the axis of the screw. In the screw driver construction shown inthe drawings, the screw engaging portion 24 is pivotally mounted on aholder 26 by means of a pin 28 arranged as shown. A slight amount ofclearance is provided between the upper end of the screw engagingportion 24 and the holder 26, so as to permit limitedoscillation of theportion 24 relative to the holder 26." Furthermore, the lower end of thescrew engaging portion 24 is slightly curved as shown at 30. By virtueof this curved arrangement, a slight misalign-- ment of thescrew driverrelative to the axis of the screw does not have as much tendency todisengage the screw driver from the slot in the screw.

As indicated in the drawings, the lower end of the screw driver has beenground, so as to form a somewhat wedge-shaped screw engagingmember whichfurther tends to prevent the screw driver from slipping out of the slotin thescrew head. By virtue of this latter construction, operation ofthe screw driver tends to pull the screw driver downwardly in the slotrather than upwardly as in the conventional screw driver designs. Thus,a

.screw driver of the type disclosed herein is especially well suited foruse in a crank type of screw driver wherein the tendency formisalignment between the shank of the screw driver and the axis of thescrew is somewhat as the holder.43 of Figure 6.

45, so. as-to. rotate. in unison. with thewshanlt. 14; at all: times;Aelatching doggortrigger 42 is pivotally supportediwithin" the. slot44%provided.,in-.the; body membe1t40; As shown: in, the drawings,, the.-body member: is cutaway; as in dicated at 46;.so as;to'pr0videazsuitable mounting flange for the: pin; 48 onwhich the trigger 42 is;pivotally: sup.- ported. The trigger 42is.providedwith: a sean-5,0-whichis adapted to engage the shoulden 52- formed on eachof the tools to beusediinthe: chucle. The shoulder 52' is formed by: cutting: acircumferentially extending; groove in the: shank. of. each; of" thetools, as shown. The: upper end of each: tool is; provided-with a:semicircular; lug or projection 54. which. is: complementary to a.similar. semicircular; lug; or. projection. 56; formed integrally with.the lower endofrthe mainshank 14;

The trigger. 42 is. at? all times .biasedinto, latchingz posiationby-the spring 60,-.and in order to. remove atool from the chuck, itisnecessary to press. on the projecting, end ofi, thetrigger so as to.disengage thesear from .the shoulder 52. In order. to support, thespring 60 within the body member,- 40, ahole; 62- is drilledv into thebody member 40,,aszbest" shown in Figure 6. The diameter of the hole 62is-slightly greater than thewidth of the slot 44,,so that a washer. 6.4placed in the. bottom of. the hole: 62- serves to, support, the inner;end of the spring,- By virtue of this arrangement, thepivot. pin 48 notonly-holds.the trigger- 42, iniassembled relationship but also serves toholdv the. spring 60 and thewasher- 64. in assembled relationship. Theprojecting; end 61 on the trigger 42 strikes. against theend-surface 63'of the slot.- 44 and. limits the inward movement of the sear portion 'ofthe. trigger.

Referringnowto-the ratchet mechanism which. is' used for transmittingpower from the: handle 12ito-the shank 14, reference numerals70 and 72designate the-upper and lower housing members. respectively of theratchet assembly. Each of these housing members consists of aninexpensive sheet metal stamping which may beheld inassembled-relationship by, any suitable means, such as-the screws-.74and the-bolt 76.which supports the handle 12. The upper end. ofthe.shank has secured thereto-a ratchet. member 78 which isdisposedbetween the'housing; members 70 and .72, as shown. Asingle ratchet:engag ing pawl 80- is slidably mounted between. the. housingmember-s70and; 72 and is: adaptedtohavezits;innerend.

arranged to. engage the teeth onthe. ratchet member. 78.

The inner endof. thepawl 80 has its one side-bevelled, as indicated. at;82, so thatin. a; first setting; of: thepawl, it will be shoved out ofengagement with theratchet teeth.

as; the: pawl: is. rotated. inthe; one: direction. but will. positivelyengage the ratchet teeth if. rotatedLimthe:opposite direction. Byrotatingthe pawlthrough 180? into a secondposition, one automatically,changes therdireetion in: which thepawh is etfcctiverto operate. Unlikeordinaryypawlsthc pawl'80 can,be set in. a neutral; position which is:midway between'the first and. second positions; just mentioned and-inthis neutral positionzit: will transmit; power. to therteeth of theratchet inbothdirections; of.r,o-

tation of the pawl. This is made possiblehythe-fact that the. bevelledportion82gfaces up rather than towards the teeth. of the ratchet whenthe-pawl isinrthe-ineutral POSl':

(i011. In this neutral position. the;straightqsidesofithe pawl engagethe teeth, as shown in.Figure.4 of. thedrawings.

The pawl 8.0 i is biased into. engagement .with the-.ratchet member bynreans.of-.a.spri11g.84 whichhas its. one end abuttingagainst. the fixedspring. support 86 riveted or otherwise secured to the housing member72, as shown. The outer or free end of the pawl is provide'd'with arecess ss-rar receiving, the one end ofthe spring 84. In

order; to facilitate free relative rotation between the spring and thepawl; a ball-bearing eiementSNI-has been'provided, as shown, at theinner end'of'the recess 88.

In order to set the pawl so as to operate the-ratchet in the desireddirection, the pawl is provided with a finger engaging wheel or knurleddisc 92 which is adapted to project through the slot 94 in the housingmember 70. A lug 96 is formed on the disc and is adapted to cooperatewith the housing member 70, so as to hold the pawl in any one of thethree desired positions. The one wall of the slot 94 is provided with anotch 98 for holding the pawl in the neutral position. The lug. 96 restsagainst the inner side of the housing in the other two positions of thepawl.

The pawl 89 is rotatably supportedbetween a. pair of complementaryfloating bearing elements 100' and 102, as shown. These bearing elementsareformed from sheet metal stampings which are held in place againstsidewise or endwise movement within the slots 104 formed in thehousingmembers 70 and. 72. Projecti0ns105 formedton the elements 100and.102. limit the outwardimovementof the bearing elements in the slots 104;

As best illustrated in Figuresv 2 and 9,,the arms of' the bearingelements 100 and 102 are. provided with inter lockingprojections and.112which serve to, hold the bearingelements in proper alignment with, one.another. It will be observed that one arm of each of the stampings' isprovided with asubstantially, U-shaped bearingslot 114. and that thecomplementary arm isprovided with. a flat bearing surface 116. By virtueof this construction, it isobvious that a limitedv amount of'misalignmentbetween the. opposed bearing elements willnot cause the pawlto.

bind; Thus, slight variations in the. dimensions of the parts. will not.cause the. pawl to bind..

In order to limit the rotation of the pawl 80,.theone: bearing element102 has secured. thereto- (-such. as. by spot welding) a U-shapedstamping element 106 which hasits upper edges arranged to limit therotational. movement of the dog 108'which is struck .up from the pawl80,. as shown.

Although the preferred embodimentof the device, has

been described; it will beunderstood that within the. purviewv of thisinvention'various changes may be made in the form, details, proportionand arrangement of' parts, the combination thereof and mode ofoperation, which generally. stated consist in-a device capableof'carrying out the objects set forth,.as. disclosed. and defined in.

the shank being attached to the ratchet wheel at'the center portionthereof and concentric therewith, the ratchet wheel beingprovided withstraight-sided teeth, a pawl for engaging saidteethslidably androtatably. supported withinthe hollow handle and normal to thelongitudinal" axis of'the shank, a plurality of fioatingbearingelements. carried by the handle and supporting the pawl, a springbiasing said pawl into engagement with the ratchetwheeh,

one end of the pawlbeing provided witha circular recess formed therein,a ball bearing partiallydisposed'within the'circul'ar recess and engagedby oneend ofthe'spring, the-other'end of the spring engagingone oftliehollow half sections; the pawl having OIIBSidEthCI'COf'bCl/Cllhd toslidably engage the teeth, the pawl also having a.

straight. side, and a' knurled knob attached tor the pawl'.

for adjusting the pawl.

References Cited in the file-of this patent UNIT ED. STATES. PATENTS12,198 Everett Jan; 9,: 1.855: 67,014 Ayres- July;'23-,..1867 207,964:Hart ....Sept.'.10; 1878 (Other references on' following page) 5 UNITEDSTATES PATENTS Abrams Sept. 9, 1879 Crockford Jan. 13, 1880 CreciliusJan. 9, 1883 Murphy July 16, 1889 Kent Dec. 17, 1889 Pratt Oct. 21, 1890Dawson July 21, 1891 Chellis Sept. 25, 1900 Charleset a1. Ian. 6, 1903Peterson Dec. 29, 1903 Mossberg Nov. 11, 1913 Carll May 4, 1915 KremerJune 19, 1917 6 Ayotte Nov. 1, 1921 Miller July 11, 1922 Morgan Aug. 8,1922 Gormley Aug. 14, 1928 Flintermann July 14, 1931 Merriman Apr. 11,1933 Lorenzer et a1. Apr. 9, 1935 Mayer June 25, 1940 3 Eastus Sept. 30,1941 Detmers Mar. 31, 1942 West Apr. 20, 1943 Foreman May 2, 1950 VosperJune 27, 1950

